staged.
None of usr.bin/clang/clang-tblgen or its dependencies need
lib/clang/include, so there is no cyclic dependency here to worry about.
The issue came about because of workarounds to dependencies on clang
being optional.
Without this, the clang-tblgen called during the build would change
after it was staged for the host. This would cause lib/clang/include to
rebuild due to changed build commands.
Sponsored by: EMC / Isilon Storage Division
Off by default, build behaves normally.
WITH_META_MODE we get auto objdir creation, the ability to
start build from anywhere in the tree.
Still need to add real targets under targets/ to build packages.
Differential Revision: D2796
Reviewed by: brooks imp
